Scaffold Drawer pull out area fix for notched devices (#24367)

* Adds fix and test

examples/flutter_gallery/ios/Runner.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

packages/flutter/lib/src/material/drawer.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:math';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 
@@ -375,6 +377,14 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
   }
 
   Widget _buildDrawer(BuildContext context) {
+    final bool drawerIsStart = widget.alignment == DrawerAlignment.start;
+    final EdgeInsets padding = MediaQuery.of(context).padding;
+    double dragAreaWidth = drawerIsStart ? padding.left : padding.right;
+
+    if (Directionality.of(context) == TextDirection.rtl)
+      dragAreaWidth = drawerIsStart ? padding.right : padding.left;
+
+    dragAreaWidth = max(dragAreaWidth, _kEdgeDragWidth);
     if (_controller.status == AnimationStatus.dismissed) {
       return Align(
         alignment: _drawerOuterAlignment,
@@ -384,7 +394,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
           onHorizontalDragEnd: _settle,
           behavior: HitTestBehavior.translucent,
           excludeFromSemantics: true,
-          child: Container(width: _kEdgeDragWidth)
+          child: Container(width: dragAreaWidth),
         ),
       );
     } else {
@@ -420,7 +430,7 @@ class DrawerControllerState extends State<DrawerController> with SingleTickerPro
                     child: FocusScope(
                       key: _drawerKey,
                       node: _focusScopeNode,
-                      child: widget.child
+                      child: widget.child,
                     ),
                   ),
                 ),

packages/flutter/test/material/scaffold_test.dart

@@ -1103,6 +1103,99 @@ void main() {
       expect(find.text('endDrawer'), findsNothing);
       expect(find.text('drawer'), findsOneWidget);
     });
+
+    testWidgets('Drawer opens correctly with padding from MediaQuery', (WidgetTester tester) async {
+      // The padding described by MediaQuery is larger than the default
+      // drawer drag zone width which is 20.
+      await tester.pumpWidget(
+        MaterialApp(
+          home: Scaffold(
+            drawer: const Drawer(
+              child: Text('drawer'),
+            ),
+            body: const Text('scaffold body'),
+            appBar: AppBar(
+              centerTitle: true,
+              title: const Text('Title')
+            ),
+          ),
+        ),
+      );
+
+      ScaffoldState scaffoldState = tester.state(find.byType(Scaffold));
+
+      expect(scaffoldState.isDrawerOpen, false);
+
+      await tester.dragFrom(const Offset(35, 100), const Offset(300, 0));
+      await tester.pumpAndSettle();
+
+      expect(scaffoldState.isDrawerOpen, false);
+
+      await tester.pumpWidget(
+        MaterialApp(
+          home: MediaQuery(
+            data: const MediaQueryData(
+              padding: EdgeInsets.fromLTRB(40, 0, 0, 0)
+            ),
+            child: Scaffold(
+              drawer: const Drawer(
+                child: Text('drawer'),
+              ),
+              body: const Text('scaffold body'),
+              appBar: AppBar(
+                centerTitle: true,
+                title: const Text('Title')
+              ),
+            ),
+          ),
+        ),
+      );
+
+      scaffoldState = tester.state(find.byType(Scaffold));
+
+      expect(scaffoldState.isDrawerOpen, false);
+
+      await tester.dragFrom(const Offset(35, 100), const Offset(300, 0));
+      await tester.pumpAndSettle();
+
+      expect(scaffoldState.isDrawerOpen, true);
+    });
+
+    testWidgets('Drawer opens correctly with padding from MediaQuer (RTL)', (WidgetTester tester) async {
+      // The padding described by MediaQuery is larger than the default
+      // drawer drag zone width which is 20.
+      await tester.pumpWidget(
+        MaterialApp(
+          home: MediaQuery(
+            data: const MediaQueryData(
+              padding: EdgeInsets.fromLTRB(0, 0, 40, 0)
+            ),
+            child: Directionality(
+              textDirection: TextDirection.rtl,
+              child: Scaffold(
+                drawer: const Drawer(
+                  child: Text('drawer'),
+                ),
+                body: const Text('scaffold body'),
+                appBar: AppBar(
+                  centerTitle: true,
+                  title: const Text('Title')
+                ),
+              ),
+            ),
+          ),
+        ),
+      );
+
+      final ScaffoldState scaffoldState = tester.state(find.byType(Scaffold));
+
+      expect(scaffoldState.isDrawerOpen, false);
+
+      await tester.dragFrom(const Offset(765, 100), const Offset(-300, 0));
+      await tester.pumpAndSettle();
+
+      expect(scaffoldState.isDrawerOpen, true);
+    });
   });
 }